125-200cc APT Smart Carb Question

OK, I know the Lectron carb has an increasing following on this site, but I have a question for the guys running Smart Carbs.

Has anybody found that their Smart Carb doesn't offer enough adjustability with the standard metering rod?

I ride in a part of the world where it is hot (80 to 90 degrees) and humid (80 to 90%). I just can't get the bike to run lean enough.

I spoke to the guys at APT and they said the carb has a usable range of 70 clicks from full rich (not 50 clicks as it says in the manual) on the low-speed adjuster. I have gone to 70, 80, 90 clicks from full rich and am still way rich.

My bike likes it LEAN: to get it running sweet I had to run a 35 pilot in my old PWK, and a special needle that JD Jetting sourced for me because neither of the needles in their standard jetting kit were lean enough.

At this point I am a little frustrated. APT initially said they would send a leaner metering rod to try, but now they say they are going to have one of their technicians call me because they don't understand how the bike can still be running rich. So far, nothing, and I am a bit gutted because I though the Smart Carb would be the END of my jetting woes!

Am I doing something stoopid ??

Yes

I would think the closer you are to sea level the richer you need to to set the carb? do you have a stuck choke? My carb is set lean but I live at 6,000'?

Thanks for the suggestion, a stuck choke could explain the rich running, particularly low-to-mid range. I will investigate.

I agree that at lower elevation, the bike runs leaner (so you must jet richer). But in my case that's offset by the fact that at warmer temperatures and higher humidity, the bike runs richer (so you must jet leaner).

I had 2 husky 125/144s while I was last living in Florida(similar temps--65-95F and 70-100% humidity) and mine generally speaking used leaner settings than most others here on the forum.

Is it spooging?

Yep it's spooging.

Humm I have the SC on my 08 CR WB165 and had no trouble dialing it in and no spooge. It does sound like the choke may be on somehow. I can't see you needing a different metering rod so something else is going on. Have you talked to a tec yet?

Not yet. Will be interesting to hear what the tec can suggest. Thanks for the input.

I hope you get it sorted out.
Just out of curiosity, do you know what your compression pressure is?

No, not checked the compression. Do you think poor compression might lead to these kinds of symptoms?

The bike was running sweet with the PWK right before the swap to the Smart Carb

But you said you had to lean out the PWK, way beyond normal-

If compression is low, you'll notice it at the bottom end the most. Will really struggle to get going and yes, will also appear to run super rich.

Thanks for the input everyone . So now the list of things to investigate is:

- possible stuck choke
- compression
- fuel type

And also to speak to the APT techs.

Thanks again.

Had another afternoon messing with the Smartcarb yesterday.

Turns out the nut that connects the choke assembly to the body of the carb had woked its way loose. This meant the choke plunger wasn't seated properly when the choke was in the off position, so the carb was continuously pulling fuel from the enrichment circuit.

Problem solved, cheers guys!

Cheers also to Corey at APT who could not have been more helpful, great customer service from those guys.

Glad you got it figured out now you can just enjoy the ride; .